Soundproofing metallic structure



Patented Mar.- 27, 1928.

UNITED STATES GEORGE L. KELLEY, OF PHILADELPHIA, PENNSYLVANIA, ASBIGNOR T0 EDWARD G. v

BUDD MANUFACTURING COMPANY, 0F PORATION OF PENNSYLVANIA.

1,664,114 PATENT OFFICE.

PHILADELPHIA, lPENNSYLVANIA, A COR- SOUNDPEOOFING METALLIC STRUCTURE.

Application led June 21,

This invention relates to soundproofing metallic structures.

The object of my invention is to provide effective and economical means fordeadening or damping the sounds metallic structures by vibrations set vup therein, so that such structures Will not be so noisy in use.

A further ob'ect of my invention is to provide a sound-proofed metallic structure and method of producing the same.

A further and more specificobject of my invention is to provide a soundproofed automobile body and method yfor producing the same. A v

A further object of my invention is to provide an effective and economical material or composition of a nature capable of application t0 the surfaces of metallic structures or parts thereof to deaden or dampen the sounds produced by vibrations set up therein.

A further object of my invention is to provide a material or composition of the nature 4referred to, which readily adheres to metallic surfaces to which itis ap lied as a coating, which dries quicklyy an when?m dry, is tough, light in weight and does not become brittle and will not flow within a temperature range from 150 F. to 30 F.

Further objects will definitely appear from the detailed description to follow. In one instance, Iv -accomplish the objects of my invention b the means set forth in the followin specification. My invention is clearly eined and pointed out in the appended claims. A structure embodying my lnventon is illustrated in the accompanying drawing, forming a part of this specification, in which the single figure is a sectional view through an automobile body treated in accordance with my invention.

When sheetv metal structures are used under conditions such that they are subjected to vibrations, objectionable drumming or rumbling noises are produced due to the vibrations set up in such structures and the consequent flexing or bending of the metal. When` such structures are used in places where other objects, sand, stones, pebbles, or the like, strike or impinge against them, this constitutes another source of objectionable noise, due to the metallic sound roduced when objects strike against the s eet produced in f 1922. semi No. seam.

metal. Such noises are exceedingly objectionable and this is particularly true of automobile bodies constructed wholly or in part of sheet metal stampings or panels.

It is among the special purposes of my invention to provide means for deadening or damping such sounds, to rovide metallic structures which are -soun proofed so that the sounds roduced by vibrations therein are deadened) or damped, and to provide a composition of such a nature and character that, when applied to the surface of a metal- .lic structure or body it serves to deaden or damp` the vibrations set up therein, when, in use, it is subjected to shocks, jars, or the like or is impinged upon by a stone, pebble or the like.

In carrying out my invention, I propose to apply a soundproong coating to the metallic structure, which is to be treated to deaden or damp sounds produced by vibrations therein. I ropose to use a coatin composition whic is easily, readily and quickly applied to the metallic surfaces of structures or y'bodies to be rendered soundroof, and which, when applied and dried, orms a tough and elastic film or coating which is not unduly softened or rendere brittle within the range of temperature likely to be encountered in use. I pro ose to provide a soundproofing composition aving the fore oing characteristics and which is economica to make and readily and easil applied. I also propose, in accordance wit my invention, to `provide a structure composed wholly or in part of sheet metal lates, panels or stampin and soundproo ed by the application to t e surface or surfaces of suoli lates, anels or stampings of a coating o soun proofing material or composition, and, particularly, in the case of an automobile body, I propose to apply the soundproofn coating to the interior surfaces of suchod so as not to interfere with the external finis or appearance.

I have discovered that a solution of asphalt inChinawood oil, or `Chinawood oil E :ra/infile 1.'

Asphalt 43 lbs., rosin 13 lbs., gilsonite 7 lbs., Chinawood oil 26 lbs., cork flou'r 5 lbs., graphite 6 lbs., drier 3 oz.

lEwa/211.21926 .Q

- Asphalt 48 lbs., rosin 21 lbs., gilsonite 7 lbs., Ghinawood oil 13.5 lbs., linseed oil 4.5

lbs., cork iiour 3 lbs., graphite 3 lbs., drier 3 oz.

The purpose of the rosin is to aid in dissolving the asphalt. The gilsonite imparts firmness to the coating composition, the cork flour gives body, and the graphite enables the composition to be appliedmoreeasily and readily with a brush. Litharge or cobait linoleate isI suitable for use as a drier. If desired, a portion of the Chinawood oil may be replaced with linseed oil as afsolvent for the asphalt, as in Example 2.

The examples given are illustrative and' I do not desire, therefore, y'o be limited or restricted to the exact ingredients and relative proportions thereof as given. The compositions produced according to either of these formulae I have found to be effective and-that produced from the formulae of examplel two is not only satisfactory, but it is also somewhatless expensive.

The composition is prepared by'mixing together the oil, rosin. and gilsonite and heating the mass to a temperature of about 400 F. continuing the heating until the solids become melted. The drier is then added, for instance, about .5% of litharge. If a very rapid drying' is desired, about .1% of cobalt linoleate may be used for the drier. The heating should be continued and increased until a temperature of about 525 F. is attained. I' have found that heating for a period of two hours is suiiicient. The asphalt is then added and afterit has become melted, the cork flour and graphite are mixed in, keeping the mixture well stirred to prevent the graphite from settling. The composition may be applied by means of a brush and, for this purpose, should be maintained at a rather high temperature. I have found that a temperature of about 320 F. is suiicientand satisfactory for this purpose although it may be applied, but with increasing diiliculty, at lesser temperatures, dowr. to 250 F. After this coating has dried, it forms a tough and somewhat elastic film or coating which adheres tenaciously to the sheet metal surfaces to which itis applied and 4will neither soften unduly nor become brittle when subjected to temperatures within the range likely to be accomplished in use, for instance, from150o F. to *30D F.

In the drawing, I have shown one specific embodiment of my invention, in which. a soundproof coating, 11, is applied to the 1nterior surfaces of the sheet metal panels 10, of an automobile body. The application of a coating, such as those above-described, to the sheet metal panels of an automoblle body, or, in fact, to any other metallic structure or body composed wholly or in parts of sheet metal panels or stampings., eliminates a great deal 4of they noise arising 1n such body in use. The coatin largely prevents the drumming or ruinb e due tothe flexing or bending of the body panels under vibration and it also deadens or dampens the metallic sound due to the strikin of objects, for instance, small stones, pe bles or the like, a ainst the body panels. This application o the soundprooiing composition in no way interferes with or impairs the external appearance or finish of the body vand `it may be eifected very cheaply and easily.

While I have shown and described my invention in connection with soundprooiing automobile bodies and while this field offers a particularly useful and desirable application of m invention, it is to ybe understood that, in t e broader scope of my invention, I a'm not to be limited or restricted with respect to such use and field of application.

I am aware that the embodiment herein disclosed may be varied considerably, without departing from the spirit of my invention and, therefore, I claim my invention broadly, as indicated by the appended claims.

Having thus decribedmy invention, what I claim as new and usefuland desire to secure by Letters Patent is:

1. A vehicle body construction comprisin a metallic body shell and a relatively thic inner lining therefor, said lining being applied to the shell in a viscous state and formed of 'such a composition that upon drying it becomes atenacious non-resilient coating lowering the vibratoryv period of the body shell.

2. A vehicle body construction comprising a sheet metal body shell and an inner tenacious lining therefor of different vibratory phase from the shell, said lining being applicable in a viscous state and formed of a composition having suspended particles of an appreciable size imparting body thereto, whereby it becomes applicable in very thick layers and the periods of vibrations produfed in the body shell during use are lowere 3. A vehicle body construction comprising i therefor, said lining being formed of a comtherefor, said interlining being formed of a position including a relatively plastic subcomposition including a relatively plastic 10 stance inert to vibrations when dry, disa halt inert to vibrations when dry, dissolved in u solvent, a comminuted material so ved in China-wood oil a comminuted ma- 5 0f Coarse texture for giving the composition terial of coarse texture for giving the cornbody, and a drying medium. position body and a drying medium.

4J A vehicle body construction comprising In testimony whereof, I aixpmy signature.

a sheet metal body shell and an inner lining GEORGE L. KELLEY. 

